Define strength parameters as functions of strains.

Question

Hi, is it possible to define a strength parameter (such as cohesion and friction angle) as a function of the deviatoric strains? 
 There are two acceptable options: 
 1. The parameters are updated along with the strains during the analyses. 
 2. The parameters are unchanged during the whole analysis where strains develop, then we update the parameters in each node, and then following analyses are conducted with the new parameters kept constant again. 
 
 For the second option, there should be a way to assign a parameter value to each node. Is this possible in plaxis? 
 Solutions that require scripting are welcome!

Dennis Waterman · Answer

Dear Nicola, 
 In principle option 1) is possible, however, there is no PLAXIS constitutive model that currently supports it. Hence, it would required you to write your own constitutive soil model. 
 Option 2) is not possible. Well, first of all because soil parameters are not determined in nodes but in stress points - but apart from that, it is not possible to change parameters in individual stress points. 
 With kind regards, 
 Dennis Waterman